ES Study Guide_Lesson1-Characteristics of Earth to Support Life.pdf

Science, Technology, Engineering and Mathematics Earth Science...

Science, Technology, Engineering and Mathematics Earth Science SY 2023-2024 Unit 1: Origin and Structure of the Earth Lesson 1: Characteristics of Earth to Support Life Introduction What makes the Earth habitable? It is the right distance from the Sun, it is protected from harmful solar radiation by its magnetic field, it is kept warm by an insulating atmosphere, and it has the right chemical ingredients for life, including water and carbon. Learning Objectives After studying this module, you should be able to: describe the characteristics of Earth that are necessary to support life. recognize the difference in the physical and chemical properties between the Earth and its neighboring planets. Pre-requisite Skills / Review REVIEW: Solar System THE SUN AND ITS PLANETS The Sun is at the center of a revolving system, trillions of miles wide, consisting of eight planets, their satellites, and numerous smaller asteroids, comets, and meteoroids. An estimated 99.85 percent of the mass of our solar system is contained within the Sun. The planets account for most of the remaining 0.15 percent. Starting from the Sun, the planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. The planets fall into two groups, based on location, size and density: the TERRESTRIAL (Earth- like) planets (Mercury, Venus, Earth, and Mars) and JOVIAN (Jupiter-like) planets (Jupiter, Saturn, Uranus and Neptune). The four terrestrial planets are also known as inner planets, and the four Jovian planets are known as the outer planets or gas giants. INTERNAL STRUCTURES After the formation of the Earth, segregation of materials formed its three layers, namely, the crust, mantle and core, depending on their chemical composition. This type of chemical separation occurred in the other planets as well. Terrestrial Planets The terrestrial planets are dense, having relatively large cores of iron and nickel. The outer cores of Earth and Mercury are liquid, whereas the cores of Venus and Mars are thought to be only partially molten. This difference is attributable to Venus and Mars having lower internal temperatures than those of Earth and Mercury. Silicate minerals and other lighter compounds make up the mantles of the terrestrial planets. Finally, the silicate crusts of terrestrial planets are relatively thin compared to their mantles. To dig deeper, watch the videos below: The Beginning of Everything - The Big Bang | https://youtu.be/lTTXzdqzMi4 The Solar System - our home in space | https://youtu.be/KsF_hdjWJjo Page 1 of 9  Science, Technology, Engineering and Mathematics Earth Science SY 2023-2024 Pre-Class Activities: 1. Watch the following supplemental videos: What If Venus and Mars Swapped Orbits? https://www.youtube.com/watch?v=LAGsa2mT_xo The End of the Habitable Zone | Space Time https://www.youtube.com/watch?v=wwGeCfWc100 2. Heuristic Reading Material: Earth as a System (page 3-7): https://rhs.rocklinusd.org/subsites/Geology/documents/CHAPTER%202%20EARTH%20AS%20 A%20SYSTEM.pdf Lesson 1.1 – Features of Venus, Earth and Mars Important Concepts to Understand: a. Escape Velocity - minimum speed an object needs to escape a planet's pull of gravity. b. Surface Pressure - atmospheric pressure at a location on the surface of the planet. It is proportional to the mass of air above the location. c. Temperature If No Greenhouse Gases Are Present: - the temperature of the Earth would be around 18°C lower without the warming effect of greenhouse gases. Take a look at the table above, study and compare planets Venus, Earth and Mars. Lesson 1.2 – Why is Earth Unique WHY EARTH IS UNIQUE? (What are the characteristics that make Earth unique among planets?) A. There is only one place in the universe, as far as we know, that supports life—a modest-sized planet called Earth that orbits an average-sized star, the Sun. B. It is found in boiling mudpots and hot springs, in the deep abyss of the ocean, and even under the Antarctic Ice Sheet. C. Living space on our planet, however, is significantly limited when we consider the needs of individual organisms, particularly humans. The global ocean covers 71 percent of Earth’s surface, but only a few hundred meters below the water’s surface, pressures are so intense that humans cannot survive without an atmospheric diving suit. In addition, many continental areas are too steep, too high, or too cold for us to inhabit Page 2 of 9  Science, Technology, Engineering and Mathematics Earth Science SY 2023-2024 TRIVIA Did you know that….. Earth was not always as we find it today. Earth was not always as we find it today. During its formative years, our planet became hot enough to support a magma ocean. It also survived a several-hundred-million-year period of extreme bombardment by asteroids. The oxygen-rich atmosphere that makes higher life-forms possible developed relatively recently. EARTH AS THE RIGHT PLANET If Earth were considerably larger (more massive), its force of gravity would be proportionately greater. Like the giant planets, Earth would have retained a thick, hostile atmosphere consisting of ammonia and methane, and possibly hydrogen and helium. If Earth were much smaller, oxygen, water vapor, and other volatiles would escape into space and be lost forever. Thus, like the Moon and Mercury, both of which lack atmospheres, Earth would be void of life. If Earth did not have a rigid lithosphere overlaying a weak asthenosphere, plate tectonics would not operate. The continental crust (Earth’s “highlands”) would not have formed without the recycling of plates. Consequently, the entire planet would likely be covered by an ocean a few kilometers deep. As author Bill Bryson so aptly stated, “There might be life in that lonesome ocean, but there certainly wouldn’t be baseball.”1 Most surprisingly, perhaps, is the fact that if our planet did not have a molten metallic core, most of the lifeforms on Earth would not exist. Fundamentally, without the flow of iron in the core, Earth could not support a magnetic field. It is the magnetic field that prevents lethal cosmic rays from showering Earth’s surface and from stripping away our atmosphere. EARTH IN THE RIGHT PLANET One of the primary factors that determine whether a planet is sui table for higher life-forms is its location in the solar system. The following scenarios substantiate Earth’s advantageous position: If Earth were about 10 percent closer to the Sun, our atmosphere would be more like that of Venus and consist mainly of the greenhouse gas carbon dioxide. As a result, Earth’s surface temperature would be too hot to support higher life-forms. Page 3 of 9  Science, Technology, Engineering and Mathematics Earth Science SY 2023-2024 If Earth were about 10 percent farther from the Sun, the problem would be reversed—it would be too cold. The oceans would freeze over, and Earth’s active water cycle would not exist. Without liquid water, all life would perish. Earth is near a star of modest size. Stars like the Sun have a life span of roughly 10 billion years. During most of this time, radiant energy is emitted at a fairly constant level. Giant stars, on the other hand, consume their nuclear fuel at very high rates and “burn out” in a few hundred million years. Therefore, Earth’s proximity to a modest-sized star allowed enough time for the evolution of humans, who first appeared on this planet only a few million years ago EARTH AT THE RIGHT TIME The last, but certainly not the least, fortuitous factor for Earth is timing. The first organisms to inhabit Earth were extremely primitive and came into existence roughly 3.8 billion years ago. From that point in Earth’s history, innumerable changes occurred—life-forms came and went, and there were many changes in the physical environment of our planet. Consider two of the many timely Earth-altering events: ✓ Earth’s atmosphere has developed over time. Earth’s primitive atmosphere is thought to have been composed mostly of methane, water vapor, ammonia, and carbon dioxide—but no free oxygen. Fortunately, microorganisms evolved that released oxygen into the atmosphere through the process of photosynthesis. About 2.5 billion years ago, an atmosphere with free oxygen came into existence. The result was the evolution of the ancestors of the vast array of organisms that occupy Earth today. ✓ About 65 million years ago, our planet was struck by an asteroid 10 kilometers (6 miles) in diameter. This impact likely caused a mass extinction during which nearly three quarters of all plant and animal species were obliterated— including dinosaurs. Although this may not seem fortuitous, the extinction of dinosaurs opened new habitats for small mammals that survived the impact. These habitats, along with evolutionary forces, led to the development of many large mammals that occupy our modern world. Without this event, mammals may not have evolved beyond the small rodent-like creatures that live in burrows. Lesson 1.3 – Factors that make a Planet Habitable (What are the characteristics of Earth to support life?) a. TEMPERATURE TOO MUCH NOT ENOUGH JUST RIGHT Low temperatures cause: Life seems to be limited to At about 125oC, protein and carbohydrate a temperature range of - molecules, and the genetic material (e.g., Chemicals to react slowly, 15oC to 115oC. In this DNA and RNA) start to break apart. which interferes with the range, liquid water can still Also, high temperatures cause the quick reactions necessary for life. exist under certain evaporation of water. conditions. It can also cause the freezing of water, making liquid water unavailable. Page 4 of 9  Science, Technology, Engineering and Mathematics Earth Science SY 2023-2024 Situation in the Solar System: Surface: only the Earth’s surface is in this temperature range. Sub-surface: the interior of the solid planets and moons may be in this temperature range b. ATMOSPHRERE TOO MUCH NOT ENOUGH JUST RIGHT Small planets and moons Earth and Venus are the Venus’s atmosphere is 100 times thicker have insufficient gravity to right size to hold a than Earth’s. It is made almost entirely of hold an atmosphere. The sufficient-sized greenhouse gasses, making the surface gas molecules escape to atmosphere. Earth’s too hot for life. The four giant planets are space, leaving the planet or atmosphere is about 100 completely made of gas. moon without an insulating miles thick. It keeps the blanket or a protective surface warm & protects it shield. from radiation & small- to medium-sized meteorites. Situation: Of the solid planets and moons, only Earth, Venus, & Titan have significant atmospheres. Mars’ atmosphere is about 1/100th that of Earth’s, too small for significant insulation or shielding c. ENERGY TOO MUCH NOT ENOUGH JUST RIGHT When there is too little sunlight With a steady input of either light energy is a problem if it or too few of the chemicals that light or chemical energy, cells makes a planet too hot or if provide energy to cells, such as can run the chemical reactions there are too many harmful iron or sulfur, organisms die. necessary for life. rays, such as ultraviolet. Too many energy-rich chemicals is not a problem. Situation:. Surface: the inner planets get too much sunlight for life. The outer planets get too little. Sub-surface: Most solid planets & moons have energy-rich chemicals. Page 5 of 9  Science, Technology, Engineering and Mathematics Earth Science SY 2023-2024 d. NUTRIENTS USED TO BUILD AND MAINTAIN AN ORGANISMS BODY TOO MUCH NOT ENOUGH JUST RIGHT Without chemicals to make All solid planets & moons Too many nutrients are not a problem. proteins & carbohydrates, have the same general However, too active a circulation system, organisms cannot grow. chemical makeup, so such as the constant volcanism on Planets without systems to nutrients are present. Those Jupiter’s moon, Io, or the churning deliver nutrients to its with a water cycle or atmospheres of the gas planets, interferes organisms (e.g., a water volcanic activity can with an organism’s ability to get enough cycle or volcanic activity) transport and replenish the nutrients. cannot support life. Also, chemicals required by when nutrients are spread living organisms. so thin that they are hard to obtain, such as on a gas planet, life cannot exist. Situation: Surface: Earth has a water cycle, an atmosphere, and volcanoes to circulate nutrients. Venus, Titan, Io, and Mars have nutrients and ways to circulate them to organisms. Sub-surface: Any planet or moon with sub-surface water or molten rock can circulate and replenish nutrients for organisms Page 6 of 9  Science, Technology, Engineering and Mathematics Earth Science SY 2023-2024 Key Concepts ❖ Escape Velocity- minimum speed an object needs to escape a planet's pull of gravity. ❖ Surface Pressure- atmospheric pressure at a location on the surface of the planet. It is proportional to the mass of air above the location. ❖ Temperature If No Greenhouse Gases Are Present: the temperature of the Earth would be around 18°C lower without the warming effect of greenhouse gases. ❖ Atmosphere is a layer or a set of layers of gases surrounding a planet or other material body, that is held in place by the gravity of that body. ❖ Temperature is the degree or intensity of heat present in a substance or object, especially as expressed according to a comparative scale and shown by a thermometer or perceived by touch. ❖ Energy is power derived from the utilization of physical or chemical resources, especially to provide light and heat or to work machines. Learning Activity Video Analysis Kindly watch the video below entitled “End of the Habitable Zone” and answer the following questions: The End of the Habitable Zone | Space Time: https://www.youtube.com/watch?v=wwGeCfWc100 1. What is the “goldilocks zone”? 2. How does the life cycle of Sun affect the life in Earth 3. Do you think we can live in Mars? Why? Why not? Page 7 of 9  Science, Technology, Engineering and Mathematics Earth Science SY 2023-2024 Enrichment Activity Directions: Read each item carefully. Write the letter of the correct answer. Multiple Choice 1. Which could possibly happen if Earth is located farther from the sun and not in the Goldilocks Zone? a. Quick evaporation of water. b. Proteins will start to denature. c. Chemical reaction will happen slowly. d. Liquid water can still exist under certain conditions. 2. Which characteristic of Earth allows the recycling of material and generates a magnetic field that protects us from radiation? a. distance from the sun b. existence of liquid water c. presence of molten core d. occurrence of the atmosphere 3. Which refers to the atmospheric pressure at a location on the surface of the planet and is proportion to the mass of air above the location? a. density b. escape velocity c. gravity d. surface pressure 4. Which refers to the minimum speed an object needs to get away from a planet’s pull of gravity? a. Density b. Gravity c. escape velocity d. surface pressure 5. What could possibly happen if the Earth’s temperature is colder than usual? a. Quick evaporation of water. b. Proteins will start to denature. c. Chemical reaction will happen slowly. d. Liquid water can still exist under certain conditions. 6. Which is NOT a factor that made Earth habitable? a. atmosphere b. energy c. exogenic processes d. temperature 7. Which does NOT show the uniqueness of the Earth to support life? a. Its molten metallic core. b. Its location around a giant star. c. Its lithosphere is lying over a weak asthenosphere. d. It contains the right amount of mass making its gravity at a right amount. 8. Which shows the uniqueness of the Earth to support life? a. existence of core b. accumulation of gas from the sun c. presence of the global magnetic field d. production of greenhouse gases in the atmosphere 9. What could possibly happen if Earth is at least 10% closer to the sun? a. There is no effect at all. b. There will be variations in the mean temperature. c. Earth’s surface temperature would be too hot to support higher life-forms. d. The oceans would freeze over, and Earth’s active water cycle would not exist. 10. Which is NOT a factor that makes Earth habitable? a. atmosphere b. energy c. rotation d. temperature Page 8 of 9  Science, Technology, Engineering and Mathematics Earth Science SY 2023-2024 Enrichment Activity Question to Ponder: Can man alter Mars environment to make it more suitable for human habitation? How? Supplemental Videos TedEd - How a single-celled organism almost wiped out life on Earth https://www.youtube.com/watch?v=dO2xx-aeZ4w&t=2s What's So Special About Earth? | Unveiled: https://www.youtube.com/watch?v=lTTXzdqzMi4 TedEd - Where did Earth’s water come from? https://www.youtube.com/watch?v=RwtO04EXgUE&t=9s TedEd - What a planet needs to sustain life? https://www.youtube.com/watch?v=9RTkZaX1cH0 Page 9 of 9